New strategies in regenerative medicine and surgery and their application to orthopedic surgery field: The bio-active composite therapies (BACTs)

Regenerative Medicine and Surgery is a rapidly expanding branch of translational research in tissue engineering, cellular and molecular biology. To date, the methods to improve cell intake, survival and isolation need to comply with a complex and still unclear regulatory frame, becoming everyday more restrictive and often limiting effectiveness and outcome of the therapeutic choices. Thus, the author developed a novel regenerative strategy, based on the synergic action of several bio-active components, called the Bio-Active Composite Therapies (BACTs) to improve grafted cells intake and survival in total compliance with the legal and ethical limits of the current regulatory frame. The rationale at the origin of this new technology is based on the evidence that cells need supportive substrate to survive in vitro and this observation, applying the concept of translational medicine, is true also in vivo. Many different sources have been used in the past for MSCs, molecules and growth factors (GF) isolation and extraction, but the Adipose Tissue and its Stromal Vascular Fraction (SVF) definitely remains the most valuable, abundant, safe and reliable. Bio-Active Composite Mixtures (BACMs) are tailor-made injectable “cocktails” containing several bio-active components to support cells survival and induce a strong regenerative response in vivo by stimulating the recipient site to act as an in-situ real Bioreactor. In this article, the author analyze the main causes of cell’s death and the strategies for preventing it, and outline all the technical steps for preparing the main components of BACMs and the different mixing modalities to obtain the most efficient regenerative action on different clinical and pathological conditions in several surgical specialties. Orthopedic Surgery is definitely the one that most can benefit of these new therapeutic strategies. The final part of this work is anticipating the logical and sequential evolution toward other fundamental technical steps for further supporting and enhancing the most efficient regenerative activity.

Photocatalytic degradation of VOCs from air stream using Mo:TiO2/GAC nanocomposites

Modification of TiO2 is one of the techniques used to enhance its photodegradation efficiency and to make it visible-light-active. In this study, Mo-doped TiO2 nanoparticles were synthesized using a fast sol-gel technique, and then coated on granular activated carbon (GAC) as both substrate and adsorbent to obtain Mo:TiO2/GAC composite. The fabricated composite was characterized using powder XRD, SEM, EDAX, FTIR, and BET analysis. Then the composite was applied to photodegrade volatile organic compounds (VOCs) under both UV and visible light irradiation. The characterization results showed high crystallinity and purity. Mo:TiO2/GAC composite had higher photodegradation efficiency compared with bare TiO2 and bare GAC. Moreover, studying operational parameters showed that the optimum condition for photodegradation efficiency of VOCs was at flowrate of 1 l/min, VOCs concentration of 20 ppm, and light intensity of 400 and 600 W/m2 for UV and visible light respectively. The results suggest that Mo:TiO2/GAC is a visible-light-active composite and can be acceptably used to decompose VOCs under visible light with adequate efficiency and without the generation of harmful by-products such as O3 as compared with UV.

The Penetration–Explosion Effects of Differently Distributed Inactive/Active Composite Shaped Charge Jets

An analysis of the penetration–explosion (PE) effects of four distributions of inactive/active composite jets shows that a well-designed inactive/active double-layer liner can promote composite jet damage. Penetration experiments were then carried out for shaped charge jets having a single inactive (Cu) liner or an inactive/active (Cu/Al) double-layer liner with variable liner height. The behaviors and firelight patterns of the different jets were captured by high-speed photography. The perforation, deformation area, and deflection were measured for each plate, showing that the Cu/Al jets have stronger PE effects. Numerical simulation shows that the tip of the composite jet generated from the full-height liner is only Cu, whereas for the other jet, from the double-layer liner, Cu is almost wrapped entirely by Al.

Layer-by-Layer-Stabilized Plasmonic Gold-Silver Nanoparticles on TiO2: Towards Stable Solar Active Photocatalysts

To broaden the activity window of TiO2, a broadband plasmonic photocatalyst has been designed and optimized. This plasmonic ‘rainbow’ photocatalyst consists of TiO2 modified with gold–silver composite nanoparticles of various sizes and compositions, thus inducing a broadband interaction with polychromatic solar light. However, these nanoparticles are inherently unstable, especially due to the use of silver. Hence, in this study the application of the layer-by-layer technique is introduced to create a protective polymer shell around the metal cores with a very high degree of control. Various TiO2 species (pure anatase, PC500, and P25) were loaded with different plasmonic metal loadings (0–2 wt %) in order to identify the most solar active composite materials. The prepared plasmonic photocatalysts were tested towards stearic acid degradation under simulated sunlight. From all materials tested, P25 + 2 wt % of plasmonic ‘rainbow’ nanoparticles proved to be the most promising (56% more efficient compared to pristine P25) and was also identified as the most cost-effective. Further, 2 wt % of layer-by-layer-stabilized ‘rainbow’ nanoparticles were loaded on P25. These layer-by-layer-stabilized metals showed superior stability under a heated oxidative atmosphere, as well as in a salt solution. Finally, the activity of the composite was almost completely retained after 1 month of aging, while the nonstabilized equivalent lost 34% of its initial activity. This work shows for the first time the synergetic application of a plasmonic ‘rainbow’ concept and the layer-by-layer stabilization technique, resulting in a promising solar active, and long-term stable photocatalyst.

Optical and Photocatalytic Properties of CuxS/ZnO Composite Thin Films Deposited by Robotic Spray Pyrolysis Deposition

This article reports on VIS-active composite thin films based on zinc oxide (ZnO) and copper sulfide (CuxS) deposited using robotic spray pyrolysis deposition (SPD) for the study of the optical and photocatalytic properties. The first step involves the SPD deposition of a CuxS layer onto the glass substrate at 300°C. The second step consists of the deposition of a ZnO layer onto the CuxS layer to form glass/CuxS-ZnO composites that were further annealed at 400°C. The development of the composite thin films was confirmed by XRD and EDX analyses. The band gap energy ( E g ) of the bare ZnO thin films decreased from 3.15 eV to an activation energy value of 2.8 eV after the deposition of the ZnO thin layer onto the CuxS layer and from 2.8 to 2.08 eV after annealing the CuxS-ZnO composite at 400°C. The UV-VIS irradiation (5.5% of UV, G = 55 W / m 2 ) of a 10 ppm methylene blue solution was used to investigate the photocatalytic properties of the CuxS-ZnO composites. The annealed CuxS-ZnO thin films at 400°C demonstrates better photocatalytic activity compared to CuxS-ZnO composites deposited at 300°C. The enhanced photocatalytic efficiency of the annealed CuxS-ZnO thin films may be the result of the diode structure and the increased crystallinity that prevent the electron-hole recombination.